Nier Replicant​ (ニーア レプリカント, Nīa Repurikanto), styled as NieR RepliCant, is an action adventure video game developed by Cavia and published by Square Enix. It was released on April 24, 2010 exclusively for the PlayStation 3. A separate game was also made for the Xbox 360 (Japan, Europe and North America) and PlayStation 3 (North America), known as NieR Gestalt. The games are based in the same world, but differ only in the lead character's design, relationship with the character of Yonah, and the time in which the game takes place.

NieR RepliCant continues off the fifth ending from the game Drakengard.An indirect sequel, titled NieR: Automata, was released on February, 2017 in Japan, and March 2017 worldwide.

Contents

The story of NieR RepliCant begins in the summer of 2053 in the ruins of an unidentified city. A prolonged snowstorm envelops the region, trapping the few survivors in a gripping cold with little shelter and minimal food. Two who have made it through the onslaught of climate change lie hunkered down in the remains of a grocery store - a boy and his sister. The girl suffers from an uncontrollable cough, while her weary brother weighs a fateful decision. The mysterious book lying on the ground between them taunts the brother with its power to help. He only needs to hand over his soul to receive the tome's power. A number of monsters known as Shades appear and the brother fights them off to protect his sister with the help of the book. After defeating the Shades the child grows sicker.

The story continues some 1,412 years in the future where a boy named Nier endures a similar struggle. His only sister has succumbed to a violent cough and must remain in bed while he searches for a cure. Though much time has passed, the world in which this brother and sister resides is, in many ways, one of a simpler time. Villagers live in modest homes and work together to ensure a better life for their community. The entire village knows of young Yonah's illness, and lends their support by hiring Nier for numerous odd jobs and errands. Some would say the work is beneath a man of his caliber, but he holds his head high and does whatever he can to provide for his sister, all the while hoping that the village's wisest member, Popola, and her twin sister Devola can discover a cure.

One day, Yonah leaves to seek out the Lunar Tear flower her brother told her about, and may have gone off in search of the Lost Shrine where Popola told her where they grow. Upon searching the Lost Shrine, Nier stumbles upon a talking book capable of wielding magic, calling itself the Grimoire Weiss. The two team up to defeat the army of Shades and two living guardian statues to save Yonah. It is discovered that Yonah is suffering from the Black Scrawl virus, which is linked to the Shades. This partnership with Weiss allows Nier to use magic, and the two begin their quest to search the lands to collect all the Sealed Verses that Nier hopes will give Weiss the power to destroy the darkness and save his sister. In their search they encounter the hot-tempered, foul-mouthed Kainé, who is herself part-Shade, and a young boy Emil, whose eyes petrify anyone that gazes upon them. Their quest sees many hardships, culminating in Kainé becoming petrified in order to seal a deadly Shade beneath the library, while Yonah is carried away by the master Shade, known as the Shadowlord, who carries his own book, Grimoire Noir.

Five years later, since Yonah was carried away, Nier has neither given up hope that she's alive nor doubts for one moment that he can find her again. Times have gotten hard for the villagers during these intervening years. The gates to the village remain shut at all times, and food is scarce. News from the outside world seldom makes it to the village because of the increased number of Shades in the neighboring plains - even many of the animals that used to graze in the southern and northern plains have fled the area. The other big difference is that the Shades have become far tougher to defeat, even for Nier. They are outfitted with plate armor and helms, and wield swords. The world is in turmoil, and the Shadowlord is behind it all.

Emil believes he has discovered the key to removing his curse as well as unpetrifying Kainé, and he and Nier journey to a lab below Emil's mansion, where Emil remembers his past: he and his sister Halua were the subjects of experiments into weapons research being conducted under the mansion as part of the "Gestalt Project". His sister, "Number 6", was utilized to create the "ultimate weapon", while he, "Number 7", was kept in reserve. This weapon - his sister - is a large, disfigured skeleton-like creature, and is ultimately defeated by Nier, but not before Emil has to seal away her power. This has the unfortunate side-effect of transforming a devastated Emil into a similar skeleton-like body that floats above the ground. However now he can see and wield his own form of magic. After unpetrifying Kainé, and defeating the Shade, the three set out to find the parts to a keystone that they believe will help them locate the Shadowlord and Grimoire Noir.

With the pieces in place, the team returns to the shrine where Weiss was originally found, in order to defeat the Shadowlord. They encounter the twins Popola and Devola, who reveal to them that all of the remaining humans on the planet are not in fact humans, but Replicants, or "shells", from the Gestalt Project. Faced with its own destruction over 1,300 years ago by a virus, mankind created the Gestalt Project in an attempt to extend human lives by transferring their minds into duplicate shells, free of disease. The project was initially successful, but the Replicants began to exert their own consciousness, and gradually became human entities of their own without the original human souls transferred into them. The Shades that Nier and people have been fighting are actually the remains of humans from long ago who have succumbed to the virus, their aggressiveness due to an overwhelming desire to return to a real body. The twins fight against Nier and his friends, but when Devola is killed Popola threatens to destroy everything until Emil sacrifices himself so that Nier and Kainé can continue.

Nier, Kainé and Weiss reach the Shadowlord's chamber and, after defeating Grimoire Noir, they discover that the Shadowlord is the original "Nier" as seen in the game's prologue, who was the primary test subject for the Gestalt Project, and driven by an identical desire to protect his sister. Having taken Yonah, he has given the original human Yonah her Replicant body, but this Yonah realizes that she cannot keep it, as she hears the Replicant Yonah calling for her brother. She vacates the body, and Nier and the Shadowlord do battle. During the fight, Weiss loses all his strength and disappears, leaving Nier to fight the Shadowlord alone. After defeating him, Nier and Yonah are reunited. However without their souls, the Replicants are doomed to extinction.

Replicant Nier is about to kill Gestalt Nier. He gazes at the Shadowlord, now having lost all hope. Replicant Nier hesitates for a second before dealing a final blow. Afterwards, Nier goes to Yonah's side. Worried when Yonah is not responding to his calls. Soon Grimoire Weiss, after losing his body, uses the last of his strength to speak. He tells Nier that she will awaken when someone says the name of the one she loves the most. The player is then given a choice to write their character's name. If entered correctly, Yonah slowly opens her eyes and observes her brother after the five years. Kainé goes to leave but is stopped by Nier, asking if she wanted to stay with them. She declines, saying she has "her own shit to take care of." The scene shifts over to Nier and Yonah back at the village, sitting on the hill near their house. Yonah runs up to a sitting Nier and gives her brother a Lunar Tear as the both lay down on the hill. The scene shifts again, showing an adult Yonah and The Shadowlord about to take each other's hand, then the adult Yonah takes hold and hugs The Shadowlord's arm, hinting that Gestalt Nier and Yonah have reunited.

Ending B starts the same as Ending A. After Replicant Nier defeats Gestalt Nier. The scene then changes to Gestalt Nier scrunched up, weeping to himself - alone in a white void - as he regrets all the hardships he put Yonah through. A flashback occurs, with Yonah and himself alone in the grocery store. He tells her that he isn't hungry, while Yonah tries to force him to eat something. The scene reverts back, and images of enemies that Replicant Nier killed gaze at him while he cries to himself. Gestalt Yonah, in her young form, comes to greet him and thanks him for always being there with her, and shares the cookie with her brother. Emil, who survived the blast, crash lands in the desert. Now just a head, he goes out to search for Nier and Kainé, bouncing and rolling into the distance.

Ending C is a continuation of endings A and B. After Nier defeats and kills the Shadowlord, as Kainé goes to leave she begins to relapse. She then goes into her shade form, forcing Nier to fight her. After Kainé is incapacitated, Tyrann explains to Nier how he can save her. Either by killing her, or forgoing his entire existence for her. If the player chooses the first option, Nier stabs Kainé as he kisses her, finally ending her pain. Tyrann tells Nier Kainé's last words: "Thank you." A lunar tear falls next to a distraught Nier. He picks it up as he gazes through a window. He then goes home and lives with Yonah, with both living out their remaining days before they die from the Black Scrawl.

If the player chooses to sacrifice his entire existence for Kainé, the player's data is erased and everyone forgets he ever existed. Nier disappears, while Yonah thanks Kainé for saving her. A lunar tear falls on the ground, which Kainé picks up. When she holds it, she has a flashback of Nier and mentions that it feels like she found something special.

Told in the novella "The Lost World" printed in GRIMOIRE NieR, the story takes place three years after Ending D. A program to reset the entire Replicant system begins its execution in the Forest of Myth.

Kainé wakes from her sleep with tears streaming down her face more and more frequently, tormented by nightmares; however, nothing but the strong feeling of losing something precious remains upon wakening. In the search to discover what this could be, she finds her way into the depths of the Forest of Myth, which has somehow been overrun with technology and wires.

It is at the center of the forest where she meets an intelligent, artificial life-form that is in charge of that particular data terminal. The terminal creates copies of Kainé to keep her away, but she eventually breaks through their ranks to find the one thing she had lost. The erased Nier is reconstructed with the “memories” that the tree had of his first visit to the Forest of Myth, essentially resetting him back to the first time he set foot into the forest at the age of 16.

Since this story is accompanied with a few images, it appears as though this is an off-shoot of Replicant as opposed to Gestalt. Therefore, there is little leeway to allow a Gestalt version of Nier in this scenario.

* This story is also alluded to on Kainé's character card from the arcade game, "Lord of Vermilion".

Nier - the title character of the game, he is described as being an "unyielding protagonist" who is trying his best to find a cure for the Black Scrawl virus which has infected his little sister, Yonah. He is voiced by Koji Yusa.

Grimoire Weiss - a hovering, magical tome, Grimoire Weiss serves as Nier's access to magical spells (known as Words in the NIER lexicon), new melee attacks and weapon upgrades. Though Nier rescues Weiss at the game's outset, his motives are suspect, a Square Enix representative commenting that "Defining Grimoire Weiss as good or evil is a difficult question, and one that the player will only truly understand after playing through NIER." Trailers have revealed other sentient books in the NIER universe. He is voiced by Peter.

Emil - a quiet, young boy who turns anything he looks at into stone. He joins Nier after trying to find a cure for his eyes. He is voiced by Mai Kadowaki

Players take control of Nier who uses his sword to perform combo attacks on his enemies; he is also able to use a magical book to shoot projectiles at enemies for a short period of time. As the player advances through the game, more powers as well as a variety of different weapons will be at the disposal of the player.

The game was first teased in the Official PlayStation 3 Magazine and Official Xbox 360 Magazine, before being officially unveiled in June 2009 at the Electronic Entertainment Expo 2009 as simply Nier for both the PlayStation 3 and Xbox 360. On September 9, 2009 Japanese gaming magazine, Famitsu , said that the version of Nier shown at E3 2009 was known as Nier Gestalt and would be released exclusively for the Xbox 360 version fueling speculation that the PlayStation 3 version of the game was canceled. However on September 15, 2009 Famitsu unveiled Nier Replicant which would be a PlayStation 3 exclusive version of the game and that it would be different from Nier Gestalt only aesthetically. For now, Gestalt will be the only version of Nier to be released in Europe and North America and will be released on both the PS3 and Xbox 360. Square Enix announced that this was because they believed the younger Nier would appeal more to the Japanese audience, while they believed the older Nier would appeal more to Western audiences. In Europe and North America, Gestalt simply went by the title NIER.

15 Nightmares is the first and only downloadable content for NieR RepliCant, and is available on Playstation Network for ￥864. It includes three battle mission packs, two new outfit sets, three new weapons, new types of Shades and new remixed tracks. Players get access to the diary of Nier's deceased mother, who died of the Black Scrawl. As the chapters of the diary progress, it shows how Nier's mother slowly succumbed to the disease, and in turn, became insane.

Oddly, in NieR RepliCant, the prologue takes place in 2053, and there is a 1,412 year time skip to the main game. In NieR Gestalt (NIER), however, the prologue takes place in 2049, and there is a 1,312 year time skip to the main game.

Similarly, Yoko Taro stated in an article from 2010 that there is a perfectly logical reason for how or why there are both Father and Brother versions of Nier. He stated that the Replicant System can replicate individuals any number of times, which would allow for individuals to be "recreated" out of sequence; sometimes their relationship would be parent/child or other times brother/sister. He does not, however, explain why the prologue in either version would feature both Father and Brother versions of Nier.